
Penta Brilliant: Faceting Design Diagram
Successful tips and guide on Faceting Designs. A Faceting Design Diagram by Jeff R. Graham that presents various cuts, this one is called "Penta Brilliant".
Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Penta Brilliant (MC82.JRG)
By Jeff R. Graham
Copyright 2002
86.5% Light Return
Angles for R.I. = 1.62
86 facets + 5 facets on girdle = 91
5-fold, mirror-image symmetry
80 index
L/W = 1.051 T/W = 0.369 T/L = 0.351
P/W = 0.470 C/W = 0.284
H/W = (P+C)/W+0.02 = 0.774
P/H = 0.607 C/H = 0.367
Vol./W^3 = 0.274
Addition # 7 - This is great in light to medium colored Quartz with no changes. Cut this in refractive indexes 1.54 to 2.14 with no changes. This is really nice in light Beryl. C2 on the crown is just cut to center point like P1 is.
Random - Cosine - ISO
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
Related Articles
Tourmaline Gem, Price, and Jewelry Information
Tourmaline Engagement Rings: the Ultimate Guide
Buying Gemstones in Afghanistan: A Beginner’s Guide
A Look at African Paraíba Tourmaline Rough
Latest Articles
Milarite Value, Price, and Jewelry Information
Appraising Pearls: How to Grade Pearls
Agate Buying Guide
Carving Techniques for Handling Inclusions in Transparent Gems
Never Stop Learning
When you join the IGS community, you get trusted diamond & gemstone information when you need it.